1. Field of the Invention
The present invention relates generally to measuring devices, measuring methods, measuring program products, measurement data editing devices, measurement data editing methods, measurement data editing program products, measurement time verifying devices, measurement time verifying methods, and measurement time verifying program products, and more particularly to a measuring device, a measuring method, a measuring program product, a measurement data editing device, a measurement data editing method, a measurement data editing program product, a measurement time verifying device, a measurement time verifying method, and a measurement time verifying program product regarding measurement data obtained by recording measurement information based on continuous measurements.
2. Description of the Related Art
Digital signing techniques and digital time-stamping techniques are employed for enhancing evidential credibility. Patent Document 1 discloses an example of a conventional technique for enhancing evidential credibility. That is, when a shutter button of a digital camera is pressed and image data are generated, position information acquired by GPS and time information is added to the image data as attribute information. Furthermore, an electronic signature is generated by using a secret key in the digital camera body, and the electronic signature is attached to the image data. Accordingly, the place and time of the photographed image data can be validated, and the image data can be used as an evidence photograph.
As popularity of digital equipment is increasing, more importance is being placed on providing evidential credibility to digital data generated by various measuring devices by attaching an electronic signature or a digital time stamp to the digital data (see, for example, Patent Document 2). It would also be convenient to be able to use digital video data recorded by a digital video camera as an evidence video.
Patent Document 1: Japanese Laid-Open Patent Application No. 2005-45486
Patent Document 2: U.S. Pat. No. 6,889,324
However, unlike photographs, video data have continuous and temporal elements. Therefore, the conventional techniques cannot be directly applied. For example, it is difficult to validate the recorded time of an arbitrary image recorded in video data. Furthermore, video data are often edited after being recorded to delete unnecessary scenes. When video data are edited, evidential credibility cannot be maintained because the electronic signature or the time stamp cannot be verified. The same problem arises not only for video data but also for any kind of data that are continuously measured with the passage of time, such as audio data.